Removal of chromium from Cr(VI) polluted wastewaters by reduction with scrap iron and subsequent precipitation of resulted cations

► We examine total removal of chromium by Cr(VI) reduction with scrap iron and subsequent precipitation of resulted cations. ► The process was detrimentally affected by a compactly passivation film occurred at scrap iron surface. ► 96.8% from the initial scrap iron still remained unreacted in the column at Cr(VI) breakthrough. ► The optimum precipitation pH range which resulted from this study is 7.6-8.0.